Fix size_of_val and min_align_of_val for truly unsized types

2 files changed, 30 insertions, 0 deletions

diff --git a/example/mini_core_hello_world.rs b/example/mini_core_hello_world.rs
index 6111e035282..aa1f239bae2 100644
--- a/example/mini_core_hello_world.rs
+++ b/example/mini_core_hello_world.rs
@@ -330,6 +330,17 @@ fn main() {
     static REF1: &u8 = &42;
     static REF2: &u8 = REF1;
     assert_eq!(*REF1, *REF2);
+
+    extern "C" {
+        type A;
+    }
+
+    fn main() {
+        let x: &A = unsafe { &*(1usize as *const A) };
+
+        assert_eq!(unsafe { intrinsics::size_of_val(x) }, 0);
+        assert_eq!(unsafe { intrinsics::min_align_of_val(x) }, 1);
+}
 }
 
 #[cfg(all(not(jit), target_arch = "x86_64", target_os = "linux"))]
diff --git a/example/std_example.rs b/example/std_example.rs
index 0a2bce2621d..0b5b6cd55d7 100644
--- a/example/std_example.rs
+++ b/example/std_example.rs
@@ -128,6 +128,25 @@ fn main() {
         0 => loop {},
         v => panic(v),
     };
+
+    if black_box(false) {
+        // Based on https://github.com/rust-lang/rust/blob/2f320a224e827b400be25966755a621779f797cc/src/test/ui/debuginfo/debuginfo_with_uninhabitable_field_and_unsized.rs
+        let _ = Foo::<dyn Send>::new();
+
+        #[allow(dead_code)]
+        struct Foo<T: ?Sized> {
+            base: Never,
+            value: T,
+        }
+
+        impl<T: ?Sized> Foo<T> {
+            pub fn new() -> Box<Foo<T>> {
+                todo!()
+            }
+        }
+
+        enum Never {}
+    }
 }
 
 fn panic(_: u128) {